Wednesday

The discovery of an increasing number of rapidly evolving objects is prompting new exploration into the extremes of the parameter space occupied by astrophysical transients, highlighting the need for prompt classification and detailed short-term follow up campaigns. Here I present new analysis of the unusual, rapidly rising and declining supernova LSQ13ddu, including modelling of its underlying power source and discussion of its possible progenitor system. Its spectral evolution transitioned from that of an SN Ibn to one more closely matching that of a SN Ic, with evidence of some residual helium within the ejecta. AT2018cow was first detected by ATLAS shortly after explosion showing a rise of more than 5 magnitudes in 3.5 days. Its rapid rise in brightness and interesting spectra triggered an intensive follow up campaign spanning from X-ray to radio wavelengths. Its light curve has been shown to be incompatible with nickel decay, with a range of other power sources suggested as potential explanations e.g. a magnetar or accretion onto a compact object. The next generation of transient surveys such as the LSST will reveal a range of objects with exotic properties and behaviours with LSQ13ddu and AT2018cow providing a small glimpse into the zoo of unusual objects awaiting discovery.